It’s a testament to the enduring draw of Tim McGraw and Faith Hill that the two can put on a tour apropos of nothing — no new album, no comeback aspirations — and still bring in fans at a turnstile-shattering rate. Their 74-date, co-headlining Soul2Soul II tour, which winds down in Las Vegas on Labor Day, has sold more than 1 million tickets, with $90 million in total revenues. Since meeting (while on tour, of course) and marrying in 1996, McGraw and Hill have since become the highest-profile country couple since June Carter and Johnny Cash, and they have done for live country what the Cashes did for country on television back in the early 1970s. The first Soul2Soul tour in 2000 was a smash, and its 2006 sequel has already landed in the record books as the highest-grossing country tour in history.